Understanding End-to-End encryption: Public and private keys

The field of cryptography is fundamental to many Blockchain systems. Cryptography, necessarily, is the practice of secure communication in the significant presence of third parties. In other words, cryptography allows the data to be stored and communicated in such a way that third parties are unable to read the contents of the communication. Cryptography used to create public and private keys, to make decentralized systems a secure network in which users can safely operate.

Computing and Internet security may be nowadays everyone’s business, but it is most critical for information technology specialists. Learning the core concepts of operating systems and network-level security helps in avoiding ongoing threats and eliminating system vulnerabilities.

Before diving into the difference between a public and a private key, we must first be aware of what a key is. A cryptographic key is a piece of information used by a cryptographic algorithm, to transform plain text into a coded form (ciphertext) or vice versa. It is this key which remains private and allows secure communication.

Of any cryptographic operation, the cryptographic key is the core part. Some cryptographic systems involve pairs of operations, such as encryption and decryption. The variable data provided as input to a cryptographic algorithm has a key as a part, to execute this kind of operation. The security of the scheme is dependent on the safety of the keys used, in a properly defined cryptographic system.

A cryptosystem is a given suite of algorithms, which generates keys. These cryptographic keys may be either symmetric or asymmetric. For symmetric encryption, only one key is required to use both encryption and decryption of data. On the other hand, two different keys needed for asymmetric encryption: one for encryption and one for decryption. The public-private pairs of the keys are provided by a certificate authority (CA) by using the public key infrastructure.

Introduction

By what we have understood above, we can thereby state the following definitions of both the public and the private key respectively:

Public key: A public key used for encryption of messages, not decryption. This key is published publicly, so that anyone who wishes to send a particular receiver a specific message securely, can do so.

Private key: Private keys, as the name tacitly suggests, are meant to be kept secret or private. A private key is used to decrypt the encrypted message that was sent using a matching public key. As compared to a public key, a private key is much faster.

Cryptographic keys can be differentiated by the purpose for which they are used. We may use this key for data encryption and decryption, digital signature verification, digital signature creation, message authentication, key transport, and key wrapping.

The length of a key generally expressed in bits. A longer key makes it more challenging to crack the encrypted data; but, a longer key result in longer periods to perform encryption and decryption processes.

The Certificate Authority provides these keys. The private key is given to the requester of the key. The public key, on the other hand, is made public in an open access directory. Private keys never travel on the Internet and thus hopefully remain private.

The Question of Ownership

A large part of security brought by cryptography concerns is about who signs a given document, or who replies at the opposite side of a connection. Assuming that keys are not compromised, that question remains of determining the owner of the corresponding public key. To be able to tell who the owner of the key is, public keys are often provided with attributes such as names, addresses, and other such similar labels. One or more supporters can digitally sign the packed collection of a public key and its characteristics. In the Public Key Infrastructure (PKI) model, the resulting object is called a certificate and signed by a certificate authority (CA). In the PGP model, it is still called a “key” and may be signed by various people who have personally verified that the attributes are similar to the subject.

In both PKI and PGP models, the compromised keys can abolish. Which has the side effect of disrupting the relationship between a key’s attributes and the subject, which may be valid. To recover from such disruption, signers often use different keys for everyday tasks. Signing with an intermediate certificate (for PKI) or a subkey (for PGP) facilitates keeping the principal private key in an offline safe.

Deleting a key on purpose to make the data inaccessible is called crypto-shredding.

How does it work?

As the key pair is mathematically connected, whatever is encrypted by a Public Key can only be decrypted by its corresponding Private Key and vice versa.

For example, if Joseph wants to send some secret data to Miranda. Also wants to be sure that only Miranda may be able to read it, then he will encrypt the data with Miranda’s Public Key. Only Miranda will have access to her corresponding Private Key. Therefore, she is the only person with the ability to decrypt the encrypted data back into its original form, the message that Joseph wanted to deliver to her originally.

As only Miranda has access to her Private Key, it is evident that only she can decrypt the encrypted data sent by Joseph. If someone else procures access to the encrypted data. it will remain confidential as they do not have access to Miranda’s Private Key.

The key must be long enough so that a hacker is unable to try all possible combinations. A key length of 80 bits is generally considered the minimum for strong security with symmetric encryption algorithms. 128-bit keys are commonly used and considered very strong.

Conclusion

The user’s digital keys are an essential element because they allow for many of the ownership features that can found in several cryptographically secure systems. It is very important to note that these digital keys not stored on those very token networks. Instead stored and created by digital token wallets, which exist independently of the network. These keys, as discussed above, are generated in pairs, consisting of a public key and private key. The public key can be thought of as being an individual’s bank account, while the private key becomes the secret PIN to that bank account.

The public key is cryptographically, connected to a digital token address in a sense that the address is the representation of the public key. It is often the case that the public key is used to generate an actual digital token address. This address serves as an identity of the user’s account to which we can pay funds.

The user’s digital keys are an essential element because they allow for many of the ownership features that can found in several cryptographically secure systems. It is very important to note that these digital keys not stored on those very token networks. Instead stored and created by digital token wallets, which exist independently of the network. These keys, as discussed above, are generated in pairs, consisting of a public key and private key. The public key can be thought of as being an individual’s bank account, while the private key becomes the secret PIN to that bank account.

The public key is cryptographically, connected to a digital token address in a sense that the address is the representation of the public key. It is often the case that the public key is used to generate an actual digital token address. This address serves as an identity of the user’s account to which we can pay funds.